Satoshi Oji

Satoshi Oji, called Prince, is a schoolboy whose mild, self-effacing manner conceals a calculating and dangerous curiosity. Aboard the Shinkansen, he keeps Kimura captive while explaining that he knew Kimura was looking for him; he also admits that he had wanted to electrocute Wataru to see how a child would react. The contrast between Prince’s harmless presentation and his stated intentions defines the menace of his introduction.

Identity and Self-Presentation

Prince gives Kimura his full name, Satoshi Oji, explaining that his surname is written with the Chinese characters for prince. He says people make fun of the unusual name and call him Prince Satoshi or simply Prince. His casual account makes the nickname sound like a joke attached to an otherwise ordinary schoolboy.

That appearance is reinforced by his account of the meeting Kimura had witnessed earlier. Prince says that he and his friends had been in the toilets but were not smoking, presenting himself as scrupulously well-behaved. The narration’s description of him as a goody two-shoes sharpens the irony: this reassuring image sits alongside an appetite for experimentation that treats another child’s fear and pain as objects of interest.

The Train Encounter and the Trap

As the Shinkansen leaves Ueno Station, Prince sits beside Kimura, opens the tray table, sets down a water bottle, and eats a chocolate. Through the window, a driving range and then a school slide into view. He considers whether the students might be his age or older, then decides that the distinction does not matter. In his view, schoolchildren and adults alike are predictable and all the same; he regards Kimura as a particularly boring example of humanity.

Kimura is not seated beside him by chance. Taped up and unable to move freely, Kimura had initially thrashed about, so Prince held Kimura’s own gun close between them and warned that he would regret failing to hear the story to its end. Prince then asks whether Kimura ever thought it strange that a boy would be riding the Shinkansen alone while Kimura could locate his seat so easily. Kimura recognizes that Prince put the information out, and Prince confirms that he knew Kimura was searching for him. The exchange recasts Kimura’s apparent discovery of Prince as a danger Prince had anticipated and used to control the encounter.

Wataru and the Intended Experiment

Kimura asks what Prince had planned to do with Wataru when they first met. Prince answers that he wanted to play with the child and see what would happen to him. He specifies that he meant an electric shock: he wanted to observe how a child of Wataru’s age would react to high voltage.

Prince points to the taser in his backpack and says that he had intended to test it, but Kimura arrived and ruined the experiment. The device makes his earlier threat concrete, while his language reduces Wataru to a test subject. Prince’s own explanation establishes both the immediate danger and the reason Kimura’s intervention mattered: it stopped him from carrying out the planned electrocution.